Tourniquet is a useful medical item to provide contracting pressure to stop local hemorrhage in a human body and also aid intravenous injection or blood drawing. Its principle is to compress veins by contracting the limbs so that the diameters of veins are shrunk smaller to hinder blood from flowing back to the heart. The obstructed blood is held in the veins and inflates the veins so that the veins are noticeable beneath the skin to facilitate fast and precise recognition to make injection or blood drawing smoother. Thus it keeps patients from discomfort caused by repetitive needling and also reduces the risk of infection.
The conventional tourniquet is a small and elongate rubber tube directly bound on a selected portion of the human body. Its small size makes binding strength difficult to control. It easily results in too much binding force and friction that make patients uncomfortable and injure the patients who have delicate skin. Rapid bouncing often occurs during unfastening that generates a great elastic returning force which might cause additional injury to patients' delicate skin. Moreover, adjusting the binding portion involves tedious repetitive unfastening and binding processes. In emergency situations such as injections are required for a great number of patients, it causes a lot of trouble for medical staff. To remedy the aforesaid problems, many improvements have been proposed in prior art. For instance, R.O.C. Patent No. M263082 entitled “Tourniquet” has a latch element coupling with a connector, a circular strap threading through the connector, and a transverse bar in the connector to form tightening of the strap. The flattened strap alleviates uncomfortable feeling of the patients caused by friction or stretching of the skin. However, as the strap winds around the cylindrical transverse bar, the strap easily slides and loosens due to the cylindrical shape. It is also difficult to fine adjust the contraction fore due to the structure of the transverse bar. The latch element and the connector also are jutting from patient's body after latched rather than positioned flatly and snuggly on patient's limbs and prone to be hit by external objects. This results in a risk of loosening the tourniquet. In environments where dust or sands are abundant, the dust or sands could scatter between the transverse bar and the strap and result in anchoring failure and loss of binding force. R.O.C. patent No. 395234 entitled “Controllable tourniquet” submitted by the Applicant provides a latch seat coupling with a connector and an elastic and circular strap to tightly binding the limbs of an user. Instead of using the transverse bar previously discussed to provide an anchoring force, a teeth surface on one end is provided to clamp the elastic strap to form a secure coupling. The coupling force is not affected by dust or sands. But it still has a deficiency by not flatly in contact with the limbs of patients, and is prone to be hit by external objects. Moreover, anchor operation by coupling the teeth surface and the elastic strap is tedious; hence it still leaves a lot to be desired.
Therefore there are still rooms for improvement on the conventional tourniquets. To develop a tourniquet that provides fast adjustment of tightening and loosening, and offers a simpler structure to reduce production cost, and is unaffected by dust or sands is still a need remained to date.